740 resultados para Curvo Semmedo, Joao.


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The aim of the present study was to evaluate the antimicrobial and cytotoxic activity of the ethanolic extract of S. cumini according to the Clinical and Laboratory Standards Institute reference method (with modifications), determining the minimal inhibitory and lethal concentration. Activity against Gram-positive (Staphylococcus aureus and S. epidermidis), Gram-negative (Pseudomonas aeruginosa) and yeast of Candida sp and Cryptococcus neoformans was evaluated. The effects of the fruit extract were examined in hamster cells ovaries in concentrations ranging from 1250.0 a 4.9 mu g/ml, measuring the reduction of the tetrazolium salt 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulphophenyl)-2H-tetrazolium. The extract showed both bactericidal and fungicidal activity among the various microorganisms tested and the MIC ranging from 7.8 to 250 mu g/ml. The MIC, MBC and MFC should values that were similar for all the microorganisms. Cytotoxicity index of the dried extract corresponded to the concentration of 400 mu g/ml. The extract could potentially be used in topical antimicrobial products. Thus, the activity of extract was potent to bacteria and mainly to non-albicans species and C. neoformans.

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This study evaluated the arterial response to cobalt-chromium stents with and without polymer coating (Camouflage (R), Hemoteq AG, Wuerselen, Germany) implanted in pigs. Cobalt-chromium balloon-expandable stents (4 x 16 mm) were implanted in the common carotid arteries of nine pigs. Histological analysis of endothelialization, inflammation and injury was performed one month later. All stents were successfully deployed, and all but one animal survived the 30 study days. All arteries were patent. Endothelialization was nearly complete in most sections of all carotid stents in both groups. There were mild inflammatory infiltrate and mild-to-moderate injury, which were associated with the stent shafts and not significantly different between groups. Our findings suggest that, in porcine carotid arteries, the histological response to balloon-expandable cobalt-chromium stents coated with polymer (Camouflage (R), Hemoteq AG) is similar to the response to non-coated cobalt-chromium stents.

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This study was undertaken to test whether the structural remodelling of pulmonary parenchyma can be sequentially altered in a model and method that demonstrate the progression of the disease and result in remodelling within the lungs that is typical of idiopathic pulmonary fibrosis. Three groups of mice were studied: (i) animals that received 3-5-di-tert-butyl-4-hydroxytoluene (BHT) and were killed after 2 weeks (early BHT = 9); (ii) animals that received BHT and were killed after 4 weeks (late BHT = 11); (iii) animals that received corn oil solution (control = 10). The mice were placed in a ventilated Plexiglas chamber with a mixture of pure humidified oxygen and compressed air. Lung histological sections underwent haematoxylin-eosin, immunohistochemistry (epithelial, endothelial and immune cells) and specific staining (collagen/elastic fibres) methods for morphometric analysis. When compared with the control group, early BHT and late BHT groups showed significant decrease of type II pneumocytes, lower vascular density in both and higher endothelial activity. CD4 was increased in late BHT compared with early and control groups, while CD8, macrophage and neutrophil cells were more prominent only in early BHT. The collagenous fibre density were significantly higher only in late BHT, whereas elastic fibre content in late BHT was lower than that in control group. We conclude that the BHT experimental model is pathologically very similar to human usual interstitial pneumonia. This feature is important in the identification of animal models of idiopathic pulmonary fibrosis that can accurately reflect the pathogenesis and progression of the human disease.

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The present study consisted of two experiments that evaluated experimental infections of Haemaphysalis leporispalustris ticks by a Brazilian strain of Rickettsia rickettsii, and their effect on tick biology. In experiment I, ticks were exposed to R. rickettsii during the larval, nymphal or adult stages by feeding on rabbits (Oryctolagus cuniculus) needle-inoculated with R. rickettsii, and thereafter reared on uninfected rabbits for the entire next tick generation. Regardless of the tick stage that acquired the infection, all subsequent tick stages were shown to be infected by PCR (infection rates varying from 1.3 to 41.7%), and were able to transmit R. rickettsii to uninfected rabbits, as demonstrated by rabbit seroconversion, guinea pig inoculation with rabbit blood, and PCR on rabbit blood. In Experiment II, ticks were exposed to R. rickettsii during the larval stage by feeding on rabbits co-infested with R. rickettsii-infected adult ticks, and thereafter reared on uninfected rabbits until the next generation of larvae. Again, all subsequent tick stages were shown to be infected by PCR (infection rates varying from 3.0 to 40.0%), and were able to transmit R. rickettsii to uninfected rabbits. Thus, it was demonstrated that larvae, nymphs, and adults of H. leporispalustris were able to acquire and maintain the R. rickettsii infection by transstadial and transovarial transmissions within the tick population, with active transmission of the bacterium to susceptible rabbits by all parasitic stages. Analyses of biological parameters of uninfected and R. rickettsii-infected tick lineages were performed in order to evaluate possible deleterious effects of R. rickettsii to the infected tick lineages. Surprisingly, all but one of the four R. rickettsii-experimental groups of the present study showed overall better biological performance than their sibling uninfected control ticks. Results of the present study showed that H. leporispalustris could support infection by a high virulent strain of R. rickettsii for at least two generations, in which infected tick lineages tended to have better performance than uninfected ticks. Our results support a possible role of H. leporispalustris in the enzootic maintenance of R. rickettsii in Latin America, as previously suggested by earlier works.

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The current Brazilian Ixodes fauna is composed of the following eight species: I. amarali Fonseca, 1935; I. aragaoi Fonseca, 1935; I. auritulus Neumann, 1904; I. fuscipes Koch, 1844; I. loricatus Neumann, 1899; I. luciae S,nevet, 1940; I. paranaensis Barros-Battesti, Arzua, Pichorim & Keirans, 2003; and I. schulzei AragA o pound & Fonseca, 1951. Further studies are needed to establish the taxonomic status of I. serrafreirei Amorim, Gazeta, Bossi & Linhares, 2003, a recently proposed species based solely on the nymphal stage. We present an up-to-date key to adults of the currently valid Brazilian species of Ixodes based on scanning electron microscopy. The relationships between Brazilian and other Neotropical Ixodes are also discussed.

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Little is known about the effect of temperature on viability of free-living phases of the life cycle of Rhipicephalus sanguineus (Latreille, 1806) despite of its importance as vector of several pathogens. Knowledge of the effect of abiotic factors on the capacity of a given tick species to infest new hosts is important for routine experimental activities under laboratory conditions, and may be relevant to understand the transmission of pathogens. The study evaluates the viability of R. sanguineus females held at 18 +/- 1, 27 +/- 1 and 32 +/- 1 degrees C and 80 +/- 5% RH (saturation deficits of 3.0, 5.3 and 7.2 mmHg, respectively) for three fasting periods (3 and 20 days and the day when female mortality reached approximately 50% after ecdysis), under laboratory conditions. In general, the best result on viability was obtained when rabbits were infested with unfed female ticks after three or 20 fasting days at both 27 +/- 1 and 32 +/- 1 degrees C and 80 +/- 5% RH.

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The present study aimed to determine whether Cryptosporidium oocysts were present in stools from captive snakes at Fundacao Parque Zoo logic (Zoological Park Foundation) in Sno Paulo, Brazil. Two collections were performed; the first in July 2008 and the second in February 2009. Fecal samples were collected from 74 enclosures that housed 101 individuals of 23 snake species. The stool specimens collected from 16 out of the 74 enclosures (21.6%) contained Cryptosporidium spp. oocysts; all of them were confirmed as Cryptosporidium serpent is, using molecular techniques. Only in three (18.7%) out of the 16 enclosures with positive samples were there animals with clinical signs compatible with infection by C. serpentis, such as regurgitation and significant progressive weight loss. From the results, it was concluded that diagnostic examinations need to be performed periodically, even on clinically healthy animals, as a preventive measure.

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Amblyomma varium Koch, 1844 is a Neotropical tick, known as the `sloth`s giant tick`, with records from southern Central America to Argentina. It is found almost exclusively on mammals of the families Bradypodidae and Magalonychidae (Xenarthra). Differences exist in discussions with regard to the dentition of the female hypostome being either 3/3 or 4/4. The male was also originally described as having a short spur on coxa IV, but some specimens recently collected from different Brazilian localities have this spur three times longer. These differences beg the question of whether there is more than one species included under this taxon. In order to answer this question and to clarify the taxonomic characters of this species, 258 adult specimens were examined, and a redescription of male and female based on light and scanning electron microscopy is provided. In addition, DNA was extracted from males with either a long or a short spur on coxa IV to help settle this question for future investigations on their taxonomy. The morphological study showed that the dental formula pattern for males and females is 3/3 and 4/4, respectively. When sequenced, the 12 S rDNA genes of both A. varium males with long and short spurs on coxa IV were found to be identical, indicating that the length of the spurs on coxa IV is likely to be an intraspecifically polymorphic character of this species.

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The present study evaluated the reproductive compatibility of the crosses between adult ticks of the following three geographically different populations of Amblyomma cajennense: State of So Paulo (SP), southeastern Brazil; State of Rondnia (RO), northern Brazil; and Colombia (CO). In addition, crosses between A. cajennense ticks from Argentina (AR) and SP ticks were also performed. The Argentinean population (AR) was compatible with SP because their crosses resulted in high % egg hatching (mean values ranging from 71.5 to 93.5%), similarly to all homologous (intrapopulational) crosses. In contrast, the tick populations SP, RO, and CO were shown to be incompatible with each other, since their heterologous (interpopulational) crosses always resulted in very low % egg hatching (range: 0-5%). The F(1) larval offspring derived from some of these females that yielded 5% egg hatching were reared until the F(1) adult stage. In all cases, only adult females molted from engorged nymphs. These F(1) females were likely to be a product of thelytokous parthenogenesis of the SP, RO, and CO females that were used in the heterologous crosses. Reproductive incompatibility is not expected to occur between different populations of a single species. Thus, our results suggest that the taxon A. cajennense might be represented by a complex of different species, whereas SP and AR ticks might represent a single species. Further populational genetic studies, coupled with extensive morphological analyses, are needed to clarify and determine a possible complex of valid species that might have been classified under the taxon A. cajennense.

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Carios mimon is an argasid tick common on Chiroptera, originally described from larvae collected on bats Mimon crenulatum from Bolivia and Eptesicus brasiliensis from Uruguay. Later it was also registered from Argentina and recently included among the Brazilian tick fauna. In Brazil, this species is very aggressive to man, resulting in intense inflammatory response and pain. It is known only by the larval description and its morphology resembles that from other species currently included into the genus Carios, formerly classified into the subgenus Alectorobius, genus Ornithodoros. Here we describe adults and redescribe the larva of C. mimon, based on light and scanning electron microscopy. Remarks about its morphological similarity with other species of this genus are also discussed. Molecular analysis inferred from a portion of the 16S rRNA mitochondrial gene placed C. mimon in a cluster supported by maximal bootstrap value (100%) with other argasid species (mostly bat parasites in the New World), which have been classified into either the genus Ornithodoros or Carios, depending on the Argasidae classification adopted by different authors.

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Ticks are hematophagous parasites of people and animals and are a public health hazard in several countries. They are vectors of infectious diseases; in addition, the bite of some ticks, mainly from the Ornithodoros genus, may lead to local lesions and systemic illness, referred to as tick toxicosis. In this report, we describe a dog bitten by Ornithodoros brasiliensis, popularly known as the mouro tick. The main clinical findings were disseminated skin rash, pruritus, mucosal hyperemia, lethargy, and fever. Laboratory abnormalities 48 hours after the bites occurred included mild nonregenerative anemia, eosinophilia, basophilia, increased serum creatine kinase activity, increased serum C-reactive protein concentration, and prolonged coagulation times. Tick-borne pathogens were not detected by PCR analysis or serologic testing, supporting the diagnosis of a noninfectious syndrome due to tick bite, compatible with tick toxicosis.

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In the beginning of the 20th century, a new canine disease was reported in Brazil under the name ""nambiuvu"", whose etiological agent was called Rangelia vitalii, a distinct piroplasm that was shown to parasitize not only erythrocytes, but also leucocytes and endothelial cells. In this new century, more publications on R. vitalii were reported from Brazil, including an extensive study on its ultrastructural analysis, in addition to clinical, pathological, and epidemiological data on nambiuvu. However, a molecular analysis of R. vitalii has not been performed to date. In the present study, we performed molecular phylogenetic analyses of R. vitalii based on fragments of the genes 18S rRNA and the heat shock protein 70 (hsp70), amplified by PCR performed on blood samples derived from five clinical cases of dogs presumably infected with R. vitalii in southern Brazil. In addition, we examined Giemsa-stained thin blood smears from these same dogs. DNA sequences (604-bp) of the 18S rRNA gene obtained from the five dogs were identical to each other, and by Blast analysis, this sequence shared the highest degree of sequence identity (95%) with Babesia sp. China-BQ1. DNA sequences (1056-bp) of the hsp70 gene obtained from the five dogs were identical to each other, and by Blast analysis, this sequence shared the highest degree of sequence identity (87%) with Babesia bigemina. Phylogenetic analyses inferred from either of the two genes resulted in the newly genotype being placed in the Babesia spp.sensu stricto clade with very high bootstrap support (95-100%) in three analyses (Neighbor-Joining, Maximum parsimony, and Maximum likelihood). Giemsa-stained thin blood smears from the dogs were shown to contain piroplasm organisms within erythrocytes, monocytes and neutrophils (individual forms), and schizont-like forms within neutrophils, in accordance with literature reports of R. vitalii. Based on these results, we conclude that R. vitalii, the etiological agent of ""nambiuvu"" in southern Brazil, is a valid species of piroplasm. Further studies are required to evaluate the validity of the genus Rangelia. (C) 2011 Elsevier B.V. All rights reserved.

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The Rhipicephalus (Boophilus) microplus BM86 and BM95 glycoproteins are homologous proteins that protect cattle against tick infestations. In this study, we demonstrated that the recombinant chimeric protein comprising tick BM95 immunogenic peptides fused to the A. marginale MSP1a N-terminal region for presentation on the Escherichia coli membrane was protective against R. microplus infestations in rabbits. This system provides a novel and simple approach for the production of tick protective antigens by surface display of antigenic protein chimera on live E. coli and suggests the possibility of using recombinant bacterial membrane fractions for vaccination against cattle tick infestations. (C) 2009 Elsevier Ltd. All rights reserved.

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Recently we conducted the molecular characterization of Rangelia vitalii, a protozoan with high pathogenicity for young dogs in southern Brazil. To date, the descriptions of the disease have been restricted to natural infection cases. Therefore, this study aimed to evaluate the parasitemia, biological cycles and clinical-pathological findings in dogs experimentally infected with R. vitalii in the acute phase of disease, and also aimed to test a therapeutic protocol based on the diminazene aceturate. For this study, we used 12 young dogs (females), separated into two groups. Group A was composed of healthy dogs, not-infected (n = 5), and Group B consisted of animals infected with R. vitalii (n = 7). After infection, the animals were monitored by blood smear examinations, which showed intra-erythrocytic forms of the parasite 5 days post-infection (PI). Parasitemia increased progressively in these animals and had the highest peak of circulating parasites between 9 and 11 days PI. Subsequently, the parasitemia reduced and the protozoan was seen inside the leukocytes in days 17, 19 and 21 PI. The most prominent clinical signs observed at the 20 day PI of experiment were lethargy, fever and anorexia. We observed a decrease of hematocrit of infected animals compared with not-infected dogs, featuring a moderate anemia. Pathological evaluation of one dog in Group B at day 21 PI revealed splenomegaly, hepatomegaly, lymphadenopathy, and hemorrhages at necropsy. Histological examination showed only follicular hyperplasia in the spleen and lymph nodes, and the etiologic agent in the vascular endothelium. At 21 days PI, it was performed the treatment of dogs in Group B (n = 6) with a single dose of diminazene aceturate, which showed a curative efficacy of 100% in cleaning R. vitalii from blood of infected dogs. (C) 2011 Elsevier Inc. All rights reserved.

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Objectives: In this work, we searched for maternal separation effects on serum corticosterone levels and blood neutrophil activity in adult male A/J and C57BL/6 mouse offspring. Methods: 40 male A/J mice and 40 male C57BL/6 mice were divided within each strain into two groups. Mice in the maternal separation group were separated from their mothers (1 h/day) on postnatal days 0-13. Mice in the control group were left undisturbed. On postnatal day 45, blood was drawn from all mice and used to assess neutrophil activity by flow cytometry and serum corticosterone levels by radioimmunoassay. Results: The results showed that each mouse strain responded differently to maternal separation, but in both cases, serum corticosterone levels were affected. In both strains, adult mice that experienced maternal separation showed lower serum corticosterone levels than control mice. In relation to control mice kept together with their mothers, the levels of serum corticosterone were 72.7 and 36.36% lower in A/J and C57BL/6 mice submitted to maternal separation, respectively. The current findings showed that maternal separation increased neutrophil activity in mice after reaching adulthood. The observed effects, although in the same direction, differed between A/J and C57BL/6 mice. Maternal separation increased both the percentage and intensity of phagocytosis in C57BL/6 mice, but had no effects on A/J mice. Furthermore, maternal separation increased basal and propidium iodide-labeled Staphylococcus aureus-induced oxidative burst in A/J mice but did not affect oxidative burst in C57BL/6 mice. Finally, phorbol myristate acetate-induced oxidative burst increased in both strains. Conclusion: These results indicate that early maternal separation increases innate immunity, most likely by modifying hypothalamus-pituitary-adrenal axis activity. This suggests that maternal separation is a good model for stress which produces long-term neuroimmune changes whatever the animal species and strain used. Copyright (C) 2011 S. Karger AG, Basel